A more acidic Arctic? NOAA deploys first buoy in region to monitor levels of CO2 absorbed by ocean

NOAA’s Pacific Marine Environmental Laboratory in partnership with the Marine Research Institute in Iceland deployed the first high-latitude ocean acidification monitoring buoy in the Atlantic Ocean in early August. The moored buoy is the first of its kind to be deployed north of the Arctic circle in a region where very little is known about how carbon dioxide (CO2) is entering the ocean environment.

New NOAA ocean acidification monitoring buoy

New NOAA buoy is first of its kind to be deployed North of the Arctic Circle. (Credit: NOAA)

The buoy, deployed north of Iceland, is equipped with a MAPCO2 monitoring system designed at PMEL that measures CO2 concentrations of the surface water and atmosphere every 90 minutes. The mooring is also equipped with pH, temperature, salinity, and oxygen sensors to provide a full picture to quantify and understand the structure of, and changes in, the North Atlantic carbonate system as the anthropogenic CO2 continues to rise.

Scientists at PMEL have been studying carbon uptake and ocean acidification in the North Pacific since 2007 on the Papa mooring in the Gulf of Alaska, but until now there was no such mooring in the North Atlantic. Quantifying and understanding variability, particularly in a region where there is vast uptake of anthropogenic CO2 from the atmosphere is critical.

"Carbon dioxide is absorbed and penetrates to much deeper levels in the North Atlantic as compared to the North Pacific,” said Jeremy Mathis, Ph.D., Oceanographer at NOAA’s Pacific Mairne Environmental Laboratory. “This buoy will help us better understand how and where our oceans are acidifying and how these waters get transported to other parts of the world.”

New buoy features MAPCO2 monitoring system

The new buoy is equipped with a MAPCO2 monitoring system that measures CO2 concentrations of the surface water and atmosphere every 90 minutes. (Credit: NOAA)

Forming the partnership with the Marine Research Institute in Iceland was simple since they have been making observations at the site and the region with regular hydrographic cruises since 1983. The addition of the North Atlantic ocean acidification buoy will provide a year round time series for the first time.

PMEL’s Carbon Program has been documenting the evolving state of the ocean carbon cycle and how it is changing over time for 30 years. The oceans are absorbing about 25% of the CO2 we release into the atmosphere and this absorption is changing the chemistry of the seawater, a process called ocean acidification.

Understanding this process is critical as more corrosive waters affect shellfish and other marine creatures. The Iceland mooring will be a crucial addition to the Global Ocean Acidification Observing Network, a new effort to knit together observations made by dozens of countries into a comprehensive picture of how ocean acidification is affecting oceans and coasts around the world.

The mooring and MAPCO2 monitoring sensor was developed and deployed by NOAA’s PMEL with support from the NOAA’s Ocean Acidification Program (OAP) and NOAA’s Ocean Climate Observation Program(OCO). This technology has been successfully transferred to the commercial sector, where is it now it now being used by scientists around the world to measure ocean acidification.